PS102 Science Fair Post Mortem

I’ll put this in the better late than never category.

The PS102 Science Fair has come and gone. Jonathan did a report on Mallard Ducks. He was quite proud of it in the end, but Maria was about ready to scream before it was done. Jonathan had to do all the illustrations and writing, but getting him to focus on it was painful. Of course, getting him to focus is painful and he needed the writing work which is why we decided a report was the correct type of project for this year.

Matthew did a report on rolling objects down an inclined plane, in this case trackball marbles (temporarily removed from my Logitech trackball mouse) and timed with a stopwatch hot-wired to a couple of phototransistors per an article from The Physics Teacher (need a reference here). The idea was to sort-of reenact Galileo’s classic work and learn about how things fall, but we fell short (bad pun intended) since I had also wanted to use several different materials for the balls in order to establish the weight independence. Good thing I didn’t try. After you do the experiment, you can calculate the moment of inertia for the trackball and you discover it is not a uniform solid sphere. If I had tried to establish the weight independence, I would have ended up having to crack open the ball to prove it wasn’t really the same as the other objects. But that might be a cool experiment….